From the Guidelines
Yes, a high heart rate (tachycardia) can be a side effect of nifedipine, as it is a calcium channel blocker that can cause vasodilation, leading to a reflex increase in heart rate 1. Nifedipine is commonly used to treat high blood pressure and angina, and its mechanism of action involves blocking calcium channels in blood vessels, resulting in vasodilation and a decrease in blood pressure. However, this vasodilation can trigger a reflex tachycardia as the body attempts to compensate for the drop in blood pressure.
Key Points to Consider
- The reflex increase in heart rate is more common with immediate-release formulations of nifedipine and typically occurs within the first few hours after taking the medication.
- Extended-release or long-acting formulations of nifedipine (such as Adalat CC or Procardia XL) are less likely to cause this side effect because they release the medication more slowly, resulting in more gradual blood pressure changes.
- If you experience persistent rapid heartbeat while taking nifedipine, you should contact your healthcare provider, as dosage adjustment or switching to a different medication might be necessary.
- According to the European Heart Journal, calcium channel blockers, including nifedipine, can cause reflex tachycardia, headache/flushing, hypotension, and falls 1.
- The 2012 ACCF/AHA focused update incorporated into the ACCF/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction also notes that nifedipine can cause hypotension, dizziness, flushing, nausea, constipation, and edema 1.
Recommendations for Management
- Monitor blood pressure and heart rate closely when initiating nifedipine therapy.
- Consider using extended-release or long-acting formulations of nifedipine to minimize the risk of reflex tachycardia.
- If reflex tachycardia occurs, consider adjusting the dosage or switching to a different medication.
- Patients should be educated on the potential side effects of nifedipine and instructed to contact their healthcare provider if they experience any symptoms of concern.
From the FDA Drug Label
With nifedipine extended-release tablets, these decreases in blood pressure are not accompanied by any significant change in heart rate In formal electrophysiologic studies, predominantly in patients with normal conduction systems, nifedipine administered as the immediate release capsule has had no tendency to prolong atrioventricular conduction or sinus node recovery time, or to slow sinus rate.
High heart rate is not a reported side effect of nifedipine, as the drug label states that there is no significant change in heart rate with nifedipine extended-release tablets 2.
From the Research
Nifedipine and Heart Rate
- Nifedipine is a calcium channel blocker that can cause reflex adrenergic stimulation, leading to an increase in heart rate 3.
- This increase in heart rate is a result of the body's response to the vasodilatory effects of nifedipine, which can mask the drug's direct inhibitory effect on myocardial contractility 3.
- Studies have shown that nifedipine can increase heart rate in patients with ischemic heart disease, particularly during the day 4.
- The increase in heart rate is associated with a reduction in parasympathetic activity, as measured by heart rate variability 4.
Clinical Evidence
- A study published in 2001 found that nifedipine retard increased heart rate in patients with ischemic heart disease, but only during the day 4.
- Another study published in 1986 found that nifedipine caused reflex adrenergic stimulation, leading to an increase in heart rate 3.
- More recent studies have focused on the safety and efficacy of immediate-release nifedipine, but have not specifically addressed the issue of heart rate as a side effect 5, 6.
Mechanism of Action
- Nifedipine works by blocking calcium channels in the heart and blood vessels, leading to vasodilation and a decrease in blood pressure 3.
- The reflex adrenergic stimulation caused by nifedipine can lead to an increase in heart rate, which can be a concern in certain patients, such as those with ischemic heart disease 3, 4.